Ignatius and the Princess III

描述
"Well, it seems the first problem is too easy. I will let you know how foolish you are later." feng5166 says.

"The second problem is, given an positive integer N, we define an equation like this:
  N=a[1]+a[2]+a[3]+...+a[m];
  a[i]>0,1<=m<=N;
My question is how many different equations you can find for a given N.
For example, assume N is 4, we can find:
  4 = 4;
  4 = 3 + 1;
  4 = 2 + 2;
  4 = 2 + 1 + 1;
  4 = 1 + 1 + 1 + 1;
so the result is 5 when N is 4. Note that "4 = 3 + 1" and "4 = 1 + 3" is the same in this problem. Now, you do it!"
输入
The input contains several test cases. Each test case contains a positive integer N(1<=N<=120) which is mentioned above. The input is terminated by the end of file.
输出
For each test case, you have to output a line contains an integer P which indicate the different equations you have found.
样例
样例输入 #1
4
10
20
样例输出 #1
5
42
627
HDOJ-1028
题目来源:HDOJ-1028
时间限制:1000 MS
内存限制:32768 KB
Java 类名:Main
64 位整数占位符:%I64d